Need a new Intel Socket P CPU

Ugh at 1.6 GHz, my laptop has become amazingly slow as of late. It's not actually that slow, but I tend to have about 20 things going at once, which makes it seem like a problem.

I own a Dell Vostro 1500, I think it's a Socket P Core 2 Duo, not sure on bus speeds and such, but it's about three years old at this point, has been around the world a few times, and is still pretty good for day to day use.

Anyhow if someone has a suggestion on what CPU can be used to upgrade this beast, please let me know.

Thanks!

Bob